Bifidobacterium sp. - Gram-positive, anaerobic, rod prokaryote. Bifidobacterium spp. are a large group of probiotic bacteria that are present in the mammalian gastrointestinal tract, mouth and vagina. They are responsible for suppressing pathogenic microorganisms and are rarely pathogenic. Infections due to some species of Bifidobacterium include obstetric and gynecological sepsis, peritonitis, pulmonary infections, urinary tract infections, bacteremia and endocarditis. Bifidobacterium spp. are used as a form of probiotic that is thought to have health promoting properties for humans. Probiotic bacteria favorably alter the intestine microflora balance, inhibit the growth of harmful bacteria, promote good digestion, boost immune function, and increase resistance to infection.

Postgrad Med, 1978 Mar, 63(3), 187 - 8, 190, 192Case report: fatal anaerobic pulmonary infection due to Bifidobacterium eriksonii; Green SL; This case illustrates progressive anaerobic pleuropulmonary infection caused by Bifidobacterium eriksonii that eventually was fatal . Aspiration pneumonia, lung abscess, empyema, and finally necrotizing pneumonia characterized the clinical course . The organism is difficult to recover, but there is reason to suspect that it may be of greater etiologic importance than heretofore recognized in debilitated patients with pleuropulmonary infections . This patient was a 52-year-old alcoholic with periodontal disease . Both conditions are well-known factors underlying anaerobic pleuropulmonary infection . Alcoholism probably predisposed the patient to aspiration of oral secretions, the likely source of the infection.http://www.bionewsonline.com/w/2/bifidobacteria_c.htm